The present invention relates to medical imaging. In particular, a system and method of automatic gain control is provided.
In many ultrasound machines, an overall gain and time gain adjustments are provided. The user rotates a knob to control the overall gain. A plurality of sliders, such as adjacent a side of a display screen, allow different gains to be applied to signals from different depths. A skilled operator increases or decreases the depth dependent gains along with the overall gain to produce an optimal image. For example, the user may adjust the gains to provide similar brightness at different depths. The user may set the overall brightness at a level desired by the user, such as to provide tissue signals at a mid or lower than middle level brightness.
U.S. Pat. No. 6,579,238 discloses an automatic gain algorithm. Signals from tissue are identified. Using the tissue signals, a surface or slowly varying spatial gain is determined to set the mean tissue signal at a target level. However, the identification of the tissue signals and/or the surface fitting may be computationally expensive.